Sometimes owners of pets will use pet restriction devices, such as pet pens, to prevent their pets from having the run of the house. While pet pens are known, existing pet pens comprise locks that make it arduous for users to unlock and open the door of the pet pen. For example, locks on existing pet pens require the user to use multiple discontinuous motions in order to unlock and open the door of the pet pen. Further, existing pet pens use locks which can result in injury to a pet. For instance, a pet inside existing pet pens can press on the door causing the edge of the door to push away from the lock and pet pen. Such a behavior of a pet while inside the pet pen can create a gap between the door and the pet pen, thereby enabling the pet to become lodged in the gap and injure itself.